Emmett Rensin wants his fellow liberals to stop being so condescending.

In an essay for Vox, he dissects what he calls "the smug style in American liberalism." It is a strain of liberalism that attributes disagreement with its tenets to stupidity and ignorance, and responds to that disagreement with mockery. It delights in evidence, however dubious, that liberals are intellectually superior to conservatives.

He believes that this style has weakened liberalism. But while his analysis is commendably large-hearted, it misses more than it sees about liberalism's flaws.

He presents some good evidence for his thesis. Remember how, a few months ago, a Democratic pollster found that 30 percent of Republican voters favored bombing Agrabah? It's the kingdom in the movie "Aladdin." Liberals sneered, as he notes.

Rensin attributes the result to Americans' excessive willingness to trust pollsters. That's charitable, and accurate: A Republican polling firm later found that 44 percent of Democrats favored taking in refugees from the same fictional country.

Rensin believes that this smugness has helped to alienate poor and working-class white voters from liberalism, and liberals from these voters. People won't vote for a politics that considers them to be hicks and rubes. Thus, he argues, liberals have failed to win votes that would help them deliver an anti-poverty agenda.

More provocatively, he thinks they have grown less interested in fighting poverty as they have become more contemptuous of the poor. They have traded labor unions for Silicon Valley, coal country for finance. Liberalism has become both less persuasive and less idealistic as a result of its conceit.

The ridicule directed at Kim Davis, the Kentucky official who refused to issue wedding licenses under her name in order to avoid doing so for same-sex couples, is one of Rensin's examples. Some liberals celebrated her imprisonment, attacked her appearance and made fun of her sexual history. Liberals, he writes, should "instead wonder what it might be like to have little left but one's values; to wake up one day to find your whole moral order destroyed; to look around and see the representatives of a new order call you a stupid, hypocritical hick without bothering, even, to wonder how your corner of your poor state found itself so alienated from them in the first place."

Rensin isn't pleading for civility, he tells us. What he wants is "class struggle," and greater respect for working-class whites is necessary for it.

This argument is not fully persuasive. Given the political constraints, Democrats have done as much as they could to help unions and, by their lights, to help the poor.

White working-class skepticism about Democrats, meanwhile, may have more to do with disagreements than with disrespect.

But more respect would be worthwhile anyway. Every political tradition needs adherents who will warn against its vices. Contemporary liberalism may be especially prone to writing off its opponents. In a 2012 article, a trio of social psychologists found that liberals had a less accurate perception of the moral views of conservatives than conservatives had of liberals. One of the authors, Jonathan Haidt, suggests over email that liberals and conservatives increasingly view each other through the stereotypes that have traditionally divided city and country folk. The urban stereotype of the rural is that they're mired in idiocy.

If liberals resist that stereotype, they may find themselves going further than Rensin does. Liberalism's defensive sneer, he writes, is "dressed up as a monopoly on reason." But if liberalism has no such monopoly, then perhaps liberals need to do more than "examine our own methods of persuasion" -- which is what he suggests.

Maybe they need to consider that some of their views are mistaken, and that the conservatives they disdain are sometimes right, even if they are working class and rural.

Maybe the economic problems of the working poor are not the result, as Rensin writes, of three decades of Republican efforts to replace "every labor law with a photo of Ronald Reagan's face." Maybe there was a way to let Kim Davis act on her conscience without causing any harm to anyone else, as her state's conservative Republican governor concluded.

The great virtue that contemporary liberalism lacks and needs is neither civility nor solidarity. It's humility -- and sadly, even some of liberalism's most thoughtful internal critics can't see it.